Patent application title: THERMAL COUNTERPANE

Abstract:

The present invention relates to a heating blanket, particularly a heating
sheet, having at least one inner layer which is constructed such that it
is permeable for warm air and faces the body to be heated by means of the
heating blanket, and at least one intermediate ply or intermediate layer
for allowing warm air through, for conveying warm air through, for
flowing warm air through and/or for transporting warm air. In order to
replace an outer layer, which is composed of polyester and polyurethane,
a coating is applied onto the intermediate layer.

Claims:

1. A heating blanket, particularly a heating sheet, havingat least one
inner layer which is constructed such that it is permeable for warm air
and faces the body to be heated by means of the heating blanket; andat
least one intermediate ply or intermediate layer for allowing warm air
through, for conveying warm air through, for flowing warm air through
and/or for transporting warm air;characterised in that a coating is
applied onto the intermediate layer.

2. A heating blanket according to claim 1, characterised in that the
coating is made from polyurethane.

3. A heating blanket according to claim 1, characterised in that the
material of the intermediate layer is at least partially formed by at
least one woven fabric and/or by at least one knitted fabric,
particularly at least partially by at least one plastic woven fabric
and/or by at least one plastic knitted fabric, specifically, at least
partially by at least one polyester woven fabric and/or by at least one
polyester knitted fabric.

4. A heating blanket according to claim 3, characterised in that a
polyurethane layer is applied.

5. A heating blanket according to claim 3, characterised in that a
polyurethane foam is applied.

6. A heating blanket according to claim 4, characterised in that
polyurethane foam is applied onto the polyurethane layer and a second
layer of polyurethane is applied onto the polyurethane foam.

7. A heating blanket according to claim 6, characterised in that the
polyurethane layers have a layer thickness of 1 to 5 mm and the
polyurethane foam is applied in a thickness of 1 to 3 cm.

8. A heating blanket according to claim 7, characterised in that the
material of the intermediate layeris both constructed so elastically that
the body to be heated can be positioned in a pressure-relieving
manner,and is constructed so rigidly that the heating blanket can only be
compressed by the body to be heated in a manner which allows allowing
warm air through, conveying warm air through, flowing warm air through
and/or transporting warm air through the intermediate layer.

9. A heating blanket according to claim 1, characterised in that the
heating blanket has at least one head region,which can at least partially
be brought into contact with the head and/or at least partially be
brought into contact with the neck of a person to be positioned on the
heating blanket and/or to be covered by the heating blanket for heating
by means of escaping warm air, and/orwhich has at least one covering
which is provided for suppressing the escape of warm air in certain
regions and can be changed at positions, and/orwhich is constructed as a
surrounding profile, at least partially for the head, and at least
partially for the neck of a person to be positioned on the heating
blanket and/or to be covered by the heating blanket.

10. A heating blanket according to claim 1, characterised in that the
heating blanket has at least one arm region which can at least partially
be brought into contact with the arm or at least partially be brought
into contact with both arms of a person to be positioned on the heating
blanket and/or to be covered by the heating blanket for heating by means
of escaping warm air and can particularly be arranged such that it
partially surrounds the arm or at least partially surrounds both arms.

11. A heating blanket according to claim 1, characterised in that the
heating blanket has at least one upper body region which can at least
partially be brought into contact with the chest and/or at least
partially be brought into contact with the back of a person to be
positioned on the heating blanket and/or to be covered by the heating
blanket for heating by means of escaping warm air and can particularly be
arranged such that it at least surrounds the chest and/or at least
partially surrounds the back.

12. A heating blanket according to claim 1, characterised in that the
heating blanket has at least one lower body region which can at least
partially be brought into contact with the lower body and/or at least
partially be brought into contact with at least one leg, particularly at
least partially with one foot of a person to be positioned on the heating
blanket and/or to be covered by the heating blanket for heating by means
of escaping warm air and can particularly be arranged such that it at
least partially surrounds the lower body and/or at least partially
surrounds the leg or at least partially surrounds the foot.

13. A heating blanket according to claim 3, characterised in that the
intermediate ply or intermediate layer and the coating are laminated to
one another.

14. A heating blanket according to claim 3, characterised in that the
intermediate ply or intermediate layer and the coating are backed to one
another.

15. A heating blanket according to claim 14, characterised in that the
side of the knitted fabric which faces the inner layer is knitted very
closely.

16. A heating blanket according to claim 13, characterised in that the
coating is present in the form of a woven fabric, particularly a
polyester, and a wind/water membrane.

17. A heating blanket according to claim 13, characterised in that the
coating is present in the form of a very close weave woven fabric,
particularly in the form of a polyester.

18. A heating blanket according to claim 1, characterised in that the
intermediate ply or intermediate layer is provided with conductive
threads.

19. A heating blanket according to claim 1, characterised in that the
coating is non-slip.

Description:

TECHNICAL FIELD

[0001]The present invention relates to a heating blanket, particularly a
heating sheet, having [0002]at least one inner layer which is
constructed such that it is permeable for warm air and faces the body to
be heated by means of the heating blanket; and [0003]at least one
intermediate ply or intermediate layer for allowing warm air through, for
conveying warm air through, for flowing warm air through and/or for
transporting warm air.

PRIOR ART

[0004]Heating blankets of the type mentioned at the beginning primarily
serve the temperature maintenance of a body positioned on the heating
blanket and/or covered by the heating blanket in that warm air is
supplied. Heating blankets of this type are used particularly, but not
exclusively, in the medical field in order to prevent heat losses from
people who are to be treated and whose independent thermoregulation is
disturbed or is temporarily rendered ineffective.

[0005]The heating blanket is here laid under and/or over the body of the
patient and the warm air which is supplied through at least one supply
hose exits distributed over an area at the inner side of the heating
blanket which faces the body, in order to heat the body.

[0006]The use of such heating blankets takes account of the fact that
especially with regard to operations, that is to say in the medical and
specifically in the surgical field, there exists an urgent requirement
for continuous and "gentle" heat supply to the human body, as, due to the
partial or full anaesthetisation which is generally required during an
operation, fundamental bodily functions are rendered partially or
completely ineffective for the duration of the anaesthetisation, so that
the danger of dangerous cooling or hypothermia of the body is very high.

[0007]At least one intermediate layer is arranged between the at least one
inner layer which faces the body and is constructed such that it is
permeable for warm air and an outer layer which faces away from the body
and is constructed such that it is substantially impermeable for warm
air. This means that the interior space or "inner space" of the heating
blanket, particularly of the heating sheet, is filled with a material
which not only ensures an allowing through of warm air, but also
guarantees a pressure-relieving positioning of anaesthetised patients and
awake patients.

[0008]The heating sheet is thus laid under the body with its inner layer
which faces the body uppermost and not only insulates the body, but heats
it convectively, that is to say using warm air which is flowing out. Just
by means of this convective heat supply, cooling or hypothermia even of a
body to be operated on can be prevented in a reliable manner. A slight
cooling is possible however.

[0009]The heating blankets known from the prior are therefore
predominantly distinguished by the following structure: [0010]as inner
layer, at least one microfibre layer which is constructed such that it is
air-permeable, that is to say is permeable for warm air; [0011]as
intermediate layer, at least one spacer/positioning woven or knitted
fabric, particularly at least one woven fabric made from synthetic fibres
or a woven or knitted polyester fabric, for allowing warm air through,
conveying warm air through, flowing warm air through and or transporting
warm air; [0012]as outer layer, at least one textile layer which is
constructed such that is air-impermeable, that is to say is impermeable
for warm air. The outer layer is a separate layer which is predominantly
composed of polyester and polyurethane coating.

[0013]It has been shown that the three-part configuration of the heating
blanket, that is to say the production of an inner layer, an intermediate
layer as well as an outer layer as separate layers which may be sewn
together requires a complex production process and is in addition
intensive in terms of material. On the other hand, it can still be
concluded that, on account of the guaranteeing of a pressure relieving
positioning of the patient, the intermediate layer fulfils a function
which cannot be dispensed with. The fact that the inner layer consists of
an air-permeable material means that the inner layer as well is of
essential importance. An air- and moisture-impermeable outer layer, which
is primarily ensured by the polyurethane integrated into the outer layer,
is also additionally required for the functionality of the heating
blanket.

DESCRIPTION OF THE INVENTION, OBJECT, SOLUTION, ADVANTAGES

[0014]Starting from the presented disadvantages and discrepancies and also
according to an evaluation of the prior art indicated, the object of the
present invention in the case of heating blankets is to construct a
heating blanket of the type mentioned at the beginning in such a manner
that while protecting the functionality of the heating blanket, a
separate layer can be dispensed with.

[0015]This object is achieved by a heating blanket with the features
specified in claim 1. Advantageous configurations and expedient
developments of the present invention are characterized in the dependent
claims.

[0016]The basic idea of the invention is to apply a coating to the
intermediate layer of a heating blanket directly. This coating can in
particular be made of polyurethane. In this manner, a further separate
layer is omitted for the heating blanket of the type mentioned at the
beginning, which blanket is composed of polyester and polyurethane. At
the same time however, the function of a separate outer layer sewn to the
intermediate layer exists in that, for example with polyurethane, there
is a material, which material is air- and water-impermeable. By applying
the polyurethane to the intermediate layer, a coating is therefore
created which replaces the separate outer layer of a heating blanket. The
application of the polyurethane layer can in this case take place in the
conventional manner in the spreading or reversal process. In this manner,
the polyurethane enters into a direct combination with the intermediate
layer, which layer can be composed of knitted fabric for example.

[0017]According to a preferred development of the present invention, the
intermediate layer is at least one plastic woven or knitted fabric, which
on the one hand is sufficiently elastic in order to guarantee a pleasant
as well as pressure-relieving lying with respect to the deformation
characteristics in the case of compressive stress, and which on the other
hand is so rigid that it can only be compressed to a limited extent, so
that the flowing through of warm air is guaranteed. The person skilled in
the art in the field of heating blankets, particularly of heating sheets,
for example a university of applied sciences engineer in the field of
textile technology with special knowledge in the field of thermodynamics
will furthermore know, with respect to the teaching of the present
invention, to appreciate that, due to the arrangement of the intermediate
ply or intermediate layer, the two other plies or layers (namely the
inner ply or inner layer as well as the outer ply or outer layer, which
is applied as a coating onto the intermediate layer) cannot be compressed
to an extent which would no longer enable allowing warm air through,
conveying warm air through, flowing warm air through and/or transporting
warm air (the side body parts are likewise heated by the warm air flowing
out of the inner ply or inner layer).

[0018]A practicable variant of the invention provides that a polyurethane
foam is applied onto the intermediate layer. A further idea of the
invention is to combine the polyurethane coating with the use of
polyurethane foam.

[0019]In this case, the polyurethane can firstly be applied onto the
intermediate layer in a certain layer thickness, wherein the polyurethane
foam for forming a core is subsequently applied, in order then to once
more apply a thin layer of polyurethane. What is produced is in one sense
a sandwich structure. With the application of a first polyurethane layer,
the intermediate layer is completely coated in order, as a result, to
initially create an air-impermeable layer. With the polyurethane foam it
is possible, in a short period of time, to build up larger layers. This
cannot be achieved with a polyurethane coating, for example in the
spreading or reversal process. The application of a further polyurethane
layer serves then to form a smooth surface as well as the securing of the
sealing of the sandwich structure. It is however also conceivable that
the polyurethane foam is applied directly onto the intermediate layer.
The fact that the polyurethane foam is applied directly onto the
intermediate layer means that a faster buildup of a layer is ensured.

[0020]When producing the sandwich structure, it is possible to proceed in
such a manner that the polyurethane layer be finished firstly, for
example in the spreading or reversal process. Then, the polyurethane
rigid foam is produced in a next step, for example by means of fluid raw
components. Finally, the polyurethane rigid foam mixture is applied to
the polyurethane layer and hardened. For forming the sandwich composite,
a further polyurethane layer can, in addition, then be applied on the
polyurethane foam in a further step. As the heating blanket should be
constructed in a heat-reflecting manner on its layer which faces away
from the body, it is advantageous that the polyurethane layer or the
sandwich structure distinguishes itself by means of a white colouring.

[0021]In the context of the present invention, the heating blanket has
[0022]at least one head region, or at least one head part, and/or
[0023]at least one arm region, or at least one arm part, and/or [0024]at
least one chest region, or at least one chest part, and/or [0025]at least
one lower body region, or at least one lower body part, and/or [0026]at
least one leg region, or at least one leg part, and/or [0027]at least one
side part and/or [0028]at least one pocket part.

[0029]These parts enable an optimal adaptation of the heating blanket to
the body circumstances of the patient. So e.g. individual arms and/or
individual legs can also be inserted into parts which are constructed in
the manner of a pocket. It is also possible that entire body parts be
covered.

[0030]An advantageous configuration of the invention provides that the
heating blanket comprises at least one head region which can be brought
into contact with the head and/or with the neck of a person covered by
the heating blanket in order to heat the head and/or the neck by means of
the warm air supplied.

[0031]The heating blanket according to the present invention does not
therefore leave the head region and/or the neck region of a patient open,
but rather includes these regions in the insulation and supplying of
heat. In this manner, a considerable improvement in the temperature
maintenance characteristics of the present heating blanket can be
achieved.

[0032]A practicable variant of the invention provides that the heating
blanket comprises at least one arm region which can be arranged in such a
manner that it surrounds the arm or a part of the arm of a person covered
by the heating blanket.

[0033]The arms of a patient can also be included in the thermoregulation
completely or in part, for example merely in the upper arm region and/or
merely in the lower arm region by means of the arm region or by means of
the preferably two arm regions. This measure as well leads to a clear
improvement of the thermic protection, as even by means of the (upper
and/or lower) arm region a considerable heat loss can occur because the
arms, like all extremities in general, are subject to the risk of a
higher degree of cooling or of hypothermia compared to the trunk.

[0034]The heating blanket can also have at least one upper body region
which can at least partially be brought into contact with the chest
and/or at least partially be brought into contact with the back of a
person to be positioned on the heating blanket and/or to be covered by
the heating blanket for heating by means of escaping warm air and can
particularly be arranged such that it at least surrounds the chest and/or
at least partially surrounds the back.

[0035]The invention additionally provides that the heating blanket has at
least one lower body region which can at least partially be brought into
contact with the lower body and/or at least partially be brought into
contact with at least one leg, particularly at least partially with one
foot of a person to be positioned on the heating blanket and/or to be
covered by the heating blanket for heating by means of escaping warm air
and can particularly be arranged such that it partially surrounds the
lower body and/or at least partially surrounds the leg or at least
partially surrounds the foot.

[0036]A further advantageous configuration of the invention provides that
the intermediate ply or intermediate layer and the coating are laminated
with one another. Textile laminates, which are also designated as bonded
fabrics, are multilayered flexible planar formed bodies which have at
least one textile which is connected to at least one further layer over
an area. A textile can likewise serve as the further layer. The laminate
connection takes place by means of material engagement and can for
example take place in such a manner that the layers, to which membranes
also belong for example, are connected to one another in accordance with
the melting or flame process. To this end, the surfaces of the layers to
be laminated are melted with appropriate temperatures and connected under
pressure. After cooling, a solid as well as flexible material is
obtained, which material combines the characteristics of its starting
materials. The laminate furthermore ensures the allowing of warm air
through.

[0037]A practicable variant of the invention provides that the
intermediate ply or intermediate layer and the coating are backed to one
another. In contrast with lamination, backing represents the connecting
of two or more woven fabric plies. The connection can take place by means
of adhesive bonding. During the adhesive bonding, very thin adhesive
films are used in accordance with the flame backing process (also
designated as bonding). As foams are also meanwhile used for backing,
backing and also the term lamination are also often used synonymously. In
the case of backing, that is to say for example in the case of the
adhesive bonding of two or a plurality of plies of the same or various
textiles e.g. the following textile planar formed bodies can be used:
woven fabrics, knitted fabrics, films, felts, paper, non-wovens, fleeces
and foam films. If a foam or another non-textile planar formed body is
connected to a textile surface, then one likewise talks of lamination. In
a further field-specific terminology, one speaks of bonding when, in the
context of thermal melting, the textile planar formed body is connected
to a lining material by means of a binder (foam).

[0038]Preferably, the side of the knitted fabric which faces the inner
layer is knitted very closely. A close knit is achieved in particular in
that the stitch density and the fineness within the knitted fabric is set
to be very fine.

[0039]In accordance with a further advantageous embodiment of the
invention, the coating is present in the form of a woven fabric,
particularly a polyester, and a wind/water membrane. The coating in the
context of the invention can also be present in the form of a very close
weave woven fabric, particularly in the form of a polyester.

[0040]The intermediate ply or intermediate layer is expediently provided
with conductive threads. The advantage of providing the intermediate ply
or intermediate layer with conductive threads can be seen in the fact
that a source of warm air can be dispensed with. Rather, the heat is
generated by the current flowing through the conductive fibres. The
intermediate layer is therefore the heat source itself. An accumulator
can be used as energy source. If the intermediate layer is present in the
form of a knitted fabric, the conductive threads are worked in, inserted
and positioned. The threads are preferably arranged in the intermediate
layer towards the patient side. The conductive threads can also be woven
into the intermediate layer. In the context of the invention the coating
can also be non-slip.

SHORT DESCRIPTION OF THE DRAWINGS

[0041]In the following, the invention is explained on the basis of the
figures. In the figures:

[0042]FIG. 1 shows a schematic illustration of a plan view onto a heating
blanket according to the invention

[0043]FIGS. 2 a) and b) show a schematic illustration of a sectional view
of the heating blanket from FIG. 1 along the section line II-II from FIG.
1

BEST WAY OF REALISING THE INVENTION

[0044]FIG. 1 shows an exemplary embodiment of a heating blanket 100
according to the invention intended for the body of a creature,
particularly of a human, which heating blanket can in each case be used,
for example in the case of operations on the body.

[0045]The heating blanket 100 has a connection 11 for an air hose 12 by
means of which warm air from a warm air source, such as can be supplied
for example from a current-driven heating apparatus or air-heating
device.

[0046]The heating blanket 100 according to the invention has the feature
that the warm air, after the switching on of the warm air source and
after passing through the air hose 12 is distributed in the intermediate
ply 16 which is constructed as an intermediate layer, which intermediate
layer is introduced into the heating blanket 100, which overall is
constructed as three ply, between the inner ply 14, which is constructed
as an inner layer and faces the body, and the outer ply 15, which is
constructed as an outer layer and faces away from the body, (the
intermediate ply or intermediate layer 16 is therefore delimited in a
manner essential to the invention by the inner ply or inner layer 14,
which faces the body, as well as by the outer ply or outer layer 15,
which faces away from the body). The inner layer or inner ply 14 is air-
and moisture-permeable as well as hydrophilic. In order to guarantee
this, the inner layer or inner ply 14 can consists of microfibre cloth
and be closed, so that a fine distribution of the air is ensured. A
strong air flow is therefore ruled out.

[0047]The provision of the intermediate ply 16 means that the warm air
provided by the warm air source can in any event be guided continuously
under the body to be warmed, so that the body parts laying on the heating
blanket 100 can be heated reliably under any circumstances.

[0048]To this end, the internal space or "inner space" of the heating
blanket 100 is filled with an intermediate-ply material made from a
plastic woven fabric, namely from polyester knitted fabric; this material
of the intermediate ply 16 is on the one hand so firm, stable and rigid
that the allowing through of warm air is ensured in a manner essential to
the invention, on the other hand even this material of the intermediate
ply 16 has a degree of elasticity which guarantees a pressure-relieving
positioning of anaesthetised patients, particularly of babies and of
small children in a manner essential to the invention.

[0049]Furthermore, both the inner ply or inner layer 14 and the outer ply
or outer layer 15 are not compressed by the arrangement of the
intermediate ply or intermediate layer 16 to such an extent that allowing
warm air through, conveying warm air through, flowing warm air through
and/or transporting warm air is no longer possible (the side body parts
are likewise warmed by means of the warm air flowing out of the inner ply
14).

[0050]The outer ply 15 of the heating blanket 100 is constructed in an
airtight, moisture-tight and air-impermeable manner here, wherefore the
outer ply 15 consists of a coating, preferably made from polyurethane,
which coating is applied directly onto the intermediate layer 16. In
principle, any woven fabric which is air- and moisture-impermeable, can
be applied onto the intermediate layer, however. This also includes
laminates or membrane coatings for example. In comparison with the
heating blankets known from the prior art, the heating blanket 100
according to the invention therefore stands out in that the outer ply 15
in the form of a coating which is applied directly onto an intermediate
layer replaces the outer ply made from a textile material of a heating
blanket or heating sheet from the prior art. The inner ply 14 of the
heating blanket 100 is air-permeable inasmuch as this inner layer 14
consists of microfibre material and, in a manner essential to the
invention, has the most finely configured openings for flowing out the
warm air supplied.

[0051]The previously mentioned technical measures lead to the fact that
the warm air can essentially escape at the inner ply 14, which inner ply
faces the body of a patient during the use of the heating blanket 100. In
this manner, the heating blanket 100 functioning as a heating sheet can
at the same time take care of an insulation against heat loss and
additionally for active heat supply.

[0052]The air-permeable inner ply 14 of the heating blanket 100 is
configured in the green shade which is conventional in operation fields.
In contrast herewith, the airtight and air-impermeable outer ply 15 is in
the form of a coating, preferably consisting of polyurethane, in a bright
colour, preferably decorated in white, so that this outer ply 15 is less
heat absorbing and also more heat reflecting and is consequently heated
less strongly.

[0053]A cooler outer surface 15 additionally has the advantage that this
outer surface 15 can less easily be dirtied by the residues of adhesive
strips, tapes or the like during the fixing of the heating blanket 100,
because the adhesive residues are less readily soluble at low
temperatures and therefore substantially remain adhering to the adhesive
strip, the tape or the like and simply not to the outer ply 14 of the
heating blanket 100.

[0054]The reuseable heating blanket 100 is therefore intended for
convective body heating and can, for example, be spread out under the
body of the patient during operations.

[0055]The heating blanket 100 is shown in the spread out state. This
heating blanket 100 has various, particularly shaped regions, wherein the
"midpoint" of the heating blanket 100 forms an upper body region 17,
which--as also in the case of known heating blankets--is to be arranged
on the chest and/or under the back of a patient.

[0056]The upper body region 17 is continued by a lower body region 20;
this lower body region 20 can cover the abdomen and also the hip part and
also the posterior part and also the legs of a patient.

[0057]A two part head region 21, 22, which is constructed in a cowl-like
manner, is also to be highlighted, [0058]which head region can be
brought partially into contact with the head and into contact with the
neck of a person to be positioned on the heating blanket 100' and to be
covered by the heating blanket 100' for heating by means of escaping warm
air, and [0059]which head region is constructed as a surrounding profile,
partially for the head, and for the neck.

[0060]Furthermore, the heating blanket 100 has arm regions 18 and 19
constructed in the manner of side parts, which arm regions can be brought
into contact with the right arm or with the left arm of a person to be
positioned on the heating blanket 100 and to be covered by the heating
blanket 100 for heating by means of escaping warm air in that the right
arm is enclosed by the left arm region 18 in the plan view illustration
of FIG. 1 and also the left arm is enclosed by the right arm region 19 in
the plan view illustration of FIG. 1.

[0061]As the arm regions 18, 19 are essentially configured in the form of
triangular tabs and consequently can also be folded or laid over a person
who is lying on their back in relation to the plan view illustration
according to FIG. 1, the arm regions 18, 19 also serve as a type of cover
with which the heating blanket 100 is equipped.

[0062]Not least for this case of the use as a cover, the previously
described arm regions 18, 19 have connection means in the form of
hook-and-loop connections 30, 31 in their respective end regions (=region
of the approximately right angle of the essentially triangular tabs),
wherein two fleece-like hook-and-loop band sections 30 which are arranged
at a distance from one another are assigned to the left arm region 18 in
the plan view illustration of FIG. 1 and a hook-like hook-and-loop band
section 31 corresponding hereto is assigned to the right arm region 19 in
the plan view illustration of FIG. 1, by means of which hook-and-loop
band sections the free ends of the arm regions 18, 19 can be fixed to one
another to form a cover.

[0063]The two arm regions 18, 19 can be connected to one another by means
of the connection means 30, 31 arranged at the ends after being laid
around the body (=chest region and/or the back region) of the patient in
order to form an upper body envelope of fixed length which keeps its
configuration and position stable.

[0064]In this context, the hook-and-loop-like connection means 30, 31 at
the ends of the two arm regions 18, 19 are arranged or set up in such a
manner that the connection means 30, 31 allow a connection of the end
regions of the arm regions 18, 19 at various angles; this makes it
possible to position the two arm regions 18, 19 in various configurations
and in various manners around the upper body or torso of the patient and
yet to ensure a secure releasable connection of the end regions.

[0065]Finally, the heating blanket 100 has at least two mutually adjacent
leg regions 23 and 24 which are of pocket-like construction and are
located below the upper body region 17, that is to say in the lower body
region 20, which leg regions are assigned to the right leg or the left
leg of a person lying on their back in relation to the plan view
illustration according to FIG. 1.

[0066]These leg regions 23 and 24 are constructed, in a manner essential
to the invention, in the form of leg bags and/or can, in a manner
essential to the invention, be releasably fixed to one another by means
of suitable connection means, such as for example by means of
hook-and-loop fasteners 32 and 33, as well as sealed, so that the warm
air supplied remains in the region of the legs and is not lost to the
outside.

[0067]The leg regions 23 and 24 can be brought at least partially in
contact with the respective leg, particularly at least partially in
contact with the respective foot, of a person to be positioned on the
heating blanket 100 and to be covered by the heating sheet 100 for
heating by means of escaping warm air, wherein the respective leg,
particularly the respective foot is enclosed by the respective leg region
23 or 24.

[0068]A section through a heating blanket 100 according to the invention,
in the case of which the polyurethane is applied onto the intermediate
layer 16, is shown in FIG. 2a). The intermediate layer 16 can be a woven
fabric and/or a knitted fabric which can be sewn to the inner layer 14.
The intermediate layer 16, which can be present in the form of a knitted
fabric, is therefore delimited by the inner layer 14, which faces the
body, and also by the polyurethane layer 27. A coating which replaces the
separate outer layer 15 of the heating blanket 10 is therefore created by
means of the application of the polyurethane onto the intermediate layer
16 and the thereby resulting polyurethane layer 27. The application of
the polyurethane layer 27 can take place in the conventional manner in
the spreading or reversal process. In this manner, the polyurethane
enters into a direct combination with the intermediate layer 16, which
layer is constructed of knitted fabric. It can be concluded that the
polyurethane layer 27 can replace the entire outer layer 15 of the
heating blanket 10 shown in FIG. 1. Thus, in the case of the conventional
heating blanket 10, the outer layer 15 composed of polyurethane and
polyester can henceforth be dispensed with. The polyurethane layer 27 can
have a layer thickness of 1 to 5 mm. Polyurethane layers of this layer
thickness stand out due to a high air-impermeability.

[0069]It can be drawn from FIG. 2b) that the intermediate layer 16, which
can also be present here as a knitted fabric, can initially be completely
coated with an application of a polyurethane layer 27, in order thereby
to initially create an air-impermeable layer. The coating can also take
place here in the spreading or reversal process. The polyurethane layer
27 can in this case be connected to a further layer which is composed of
polyurethane foam 28. A polyurethane layer 27 is in turn applied onto the
polyurethane foam 28. What is produced in this manner is in one sense a
sandwich structure, which has a core with the polyurethane foam 28 and
has top layers with the polyurethane layers 27. The polyurethane foam 27
which is applied directly onto the intermediate layer 16, which is
constructed as a knitted fabric, initially constitutes the
air-impermeable layer for the heating blanket 100. With the application
of the polyurethane foam 28, it is then possible in a short space of time
to build up larger layers which cannot be achieved by means of the
spreading or reversal process. The application of a further polyurethane
layer 27 serves the further sealing of the sandwich structure and thus
also a further increased air-impermeability.

[0070]It is also possible in the context of the invention that the
intermediate ply or intermediate layer 16 and the coating are laminated
or backed to one another. Additionally, the side of the intermediate ply
or intermediate layer 16 which is present as a knitted fabric and faces
the inner layer can also be knitted very closely.

[0071]In order to be able to dispense with the warm air source 13 and the
air hose 12 shown in FIG. 1, the intermediate ply or intermediate layer
16 of the heating blanket 100 can also be provided with conductive
threads, the current source of which can in turn be an accumulator.